Conventionally, a variety of proposals are made with respect to a method of moulding a composite member. For example, a moulding method proposed in Japanese Patent Publication (KOKOAI) H8-99331 is such that a polypropylene resin is melted and injection moulded in a metal mould to mould a polypropylene member, and the resulting moulded product is inserted into another metal mould, and a thermoplastic elastomer is melted and ejected on a surface of the polypropylene member, whereby a thermoplastic elastomer member is fusion bonded and moulded on the surface of the polypropylene member integrally and three-dimensionally. The composite member including such two materials is such that the thermoplastic elastomer member is formed on one surface of the polypropylene resin.
Further, Published Japanese Translation (KOHYO) No. 2003-512960 discloses that two-component injection moulding (two-shot molding) is carried out using different thermoplastic elastomers to form a grip for a writing instrument of two layers with different hardness.    Patent Document 1: Japanese Patent Publication (KOKOAI) H8-99331    Patent Document 2: Published Japanese Translation (KOHYO) No. 2003-512960